DE 2 026 509 A discloses a cutting head for a hair and/or beard cutting appliance, the cutting head comprising a stationary comb shaped as a basically tubular laterally extending body, the tubular body comprising two laterally extending bent protruding sections facing away from each other, wherein each bent section comprises a first wall portion and a second wall portion that extend into a common tip portion, the first wall portion and the second wall portion surrounding a guide area for a movable blade, wherein the bent sections comprises a plurality of slots in which to-be-cut hairs can be trapped and guided towards the movable blade during a cutting operation. The movable blade comprises a basically U-shaped profile that cooperates with the first and the second bent section, wherein each leg of the U-shaped profile comprises an outwardly bent edge portion extending into the guide area defined by the respective first and second wall portion, the edge portion further comprising a toothed cutting edge for cutting trapped hair in a relative motion between the toothed cutting edge of the movable blade and a toothed edge of the stationary comb defined by the plurality of slots in the first and the second bent section.
U.S. Pat. No. 2,948,063 A discloses a head for a dry shaver comprising a cutter having a pair of outwardly extending flanges, two rows of cutter teeth defined along the outer ends of said flanges, depressed portions formed in said flanges parallel to and immediately adjacent said rows of teeth to strengthen said flanges and prevent twisting thereof, the portion of each said flange connecting the row of teeth to said depressed portion extending downwardly at a sharp angle to the plane defined by the upper face of said teeth, and comprising a comb having two rows of teeth thereon and resilient means biasing said cutter teeth into engagement with said comb teeth, said flanges engaging said comb only along said two rows of cutter teeth.
U.S. Pat. No. 2,290,326 A discloses a shearing device comprising a casing, a blade holder affixed to the forward end of said casing, said holder having a pair of clamps each with an inturned protruding lip adapted to overlap the corresponding end of a shearing blade assembly, clamp closing means within the holder and means associated with the respective clamps and exposed for manual operation to permit opening said clamps for release of the shearing blade assembly.
For the purpose of cutting body hair, there exist basically two customarily distinguished types of electrically powered appliances: the razor, and the hair trimmer or clipper. Generally, the razor is used for shaving, i.e. slicing body hairs at the level of the skin so as to obtain a smooth skin without stubbles. The hair trimmer is typically used to sever the hairs at a chosen distance from the skin, i.e. for cutting the hairs to a desired length. The difference in application is reflected in the different structure and architectures of the cutting blade arrangement implemented on either appliance.
An electric razor typically includes a foil, i.e. an ultra thin perforated screen, and a cutter blade that is movable along the inside of and with respect to the foil. During use, the outside of the foil is placed and pushed against the skin, such that any hairs that penetrate the foil are cut off by the cutter blade that moves with respect to the inside thereof, and fall into hollow hair collection portions inside the razor.
An electric hair trimmer, on the other hand, typically includes generally two cutter blades having a toothed edge, one placed on top of the other such that the respective toothed edges overlap. In operation, the cutter blades reciprocate relative to each other, cutting off any hairs that are trapped between their teeth in a scissor action. The precise level above the skin at which the hairs are cut off is normally determined by means of an additional attachable part, called a (spacer) guard or comb.
Furthermore, combined devices are known that are basically adapted to both, shaving and trimming purposes. However, these devices merely include two separate and distinct cutting sections, namely a shaving section comprising a setup that matches the concept of powered razors as set out above, and a trimming section comprising a setup that, on the other hand, matches the concept of hair trimmers.